Electric heating element for stoves



' Jan. 20. 1925.

C. C. ARMSTRONG ELECTRIC HEATING ELEMENT FOR STOVES Filed March 18. 1924 awveutoz umren STA-T Patented Jan. 20,1925. 1

' CHARLES CARRQLL ARMSTRONG, O'F HUNTINGTON; WEST VIRGINIA.

,- ELEcrnIc HEATING ELEMENT FOR STOVES;

To all whom it-may concern."

Be, it known that I, CHARLES, 0, Ann- STRONG, a citizen of the United States, and resident of Huntington, in the county ,of Cabell and 'State of. West Virginia, have inventedcertain new and useful Improvements in Electric Heating Elements for Stoves, of which the following is a specification.

heating coil or electric conductor being shown.

Fig. 2' is a sectional view of Fig. 1. Fig. 3 is-a cross sectional view of a portion of the clay body of the heating ele-- ment with its coil retaining projection part- ,ly formed.

Fig. 4 is a cross sectional view similar to Fig. 3 with the coil retaining projection completely formed and the electric heating-coil in place. these drawings 1 indicates the mam 7 body of the heating element, which "is mold-v ed from material of high heat resisting qualities, as for instance, clay. The body is in the form of a circular plate having a oove 2 in its upper face, this preferably.

1 tical rib as shown by the dotted line in Fig. ed to receive the coil of wire which rebeing of spiral form.- This groove is a'daptceives the electric current and furnishes the heat for cooking. f

In order to retain the heating coil in place, projections 3 are formed as a part of the molded body and these projections extend from the upper portions of the wall of the groove transversely and .thus overhang the main portion of the groove in which the heating coil is seated. In the best form of the invention the lugs extend only part way across the oove, and opposite each projectioh there 1s formed in the other wall of the groove a recess 4 conforming generally in shape to the curved contour of the projection, so that the coil can be inserted into place through the gate thus formed without undue stretching or distortion and without having to drag the coil Application filed lfarch 18, 1924. SerialNo. 700,046.

along the groove. The coil is slipped into place under the projection by introducing it able number of these projections and re cesses and they may be located out of radial alignment as shown.

In the formation of these projections it is one object of the present invention to avoid the occurrence 'of openings through the plate belowthese projections which have been necessitated in-a prior process in order to provide these overhangin projections in the act of molding the p ate. In this prior process it has been the practice to mount pins on the lower mold section of. the, same or greater cross sectional area as the area of the projections. These pins formed the means for shaping the under side of the lugs or projections.

When the molded body is removed from the mold openings are left at the points where the pins occur and these openin extend entirely through the body of e heating member from the bottom of the groove to the lower face, and are objectionable because of the loss of heat therethrough.

through the recess. -There are a consider- I They are objectionable also because of 3, with a small milling cutter mounted on a flexible shaft. This milling cutter is of proper shape that after performing its work 1 the projection will have assumed the form shown in Fig. 4, ready to receive the coil of conducting wire beneath it. The body of the plate is left intact and continuous at the bottom of the oove, no opening being present at the point below the overhang and hence the radiation of heat from the coil will be entirely upward, there. being no openings for its wasteful escape downwardly.

After the undercutting is done the body is ready to be baked to harden -the material. J I I.

I claim:

1.- A heating element for electric stoves and the like comprising a heating coil, 9.

body spirally grooved on its upper face I s i with overhanging pro ections at intervals along. the groove extending transversely of the groove at the upper part thereof, the wall of the groove opposite said projections being recessed to 'form gates for the introduction of the heating coil below said projections, the width of the-groove being substaiitially the same as the diameter of the C01 2. A heating element for electric stoves and the like comprising a heating coil, a

body spirally grooved on its u er face with overhanging projections at intervals along the groove extending transversely of the groove at the upper part thereof, the.

wall of the groove opposite said projections being recessed to form gates for the introduction of the heating coil below said 20 projections, said projections extending from the side of the groove which is nearest the center of the element, the width of the groove being substantially the same as the diameter of the coil.

3. The hereindescribed process of making heating elements consisting in moldlng' a body of heat resisting material grooved body below the projections continuous along i the bottom' of the groove and continuous,

said body, subwith the rest of the mass of stantially as described.

In testimony whereof, I .aflix my signature. o

CHARLES CARROLL ARMSTRONG. 

